The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingRegistration
Perform vehicle stability control system recognition in ecm
Notice:
If the vehicle has both cruise control and vsc, when
replacing ecm, perform vsc recognition as follows:
Turn the ignition switch on.
After waiting approximately 5 seconds, turn the
cruise control main switch on.
Ke ...
Back-up light circuit
Description
The park / neutral position switch turns on when the shift lever is moved
into the r position, causing the
back-up lights to illuminate.
Wiring diagram
Inspection procedure
Inspect fuse (gauge1)
Remove the gauge1 fuse from the instrument panel
junction block.
Meas ...
Shift solenoid "d" performance (shift solenoid valve s4)
System description
The ecm uses signals from the output shaft speed sensor and input speed
sensor to detect the actual
gear position (1st, 2nd, 3rd or o/d gear).
Then the ecm compares the actual gear with the shift schedule in the ecm memory
to detect mechanical
problems of the shift s ...